The invention relates generally to streaming video through a data network and, more particularly, to integrating still images into a stream of live, moving images.
Many companies and education institutes have tried to use the Internet for distributing documentation of seminars, meetings, lectures, etc. including video. Those who have tried know that one problem is the cost for the video post-production, and that it is impossible to be able to send the material on the Internet when it is fresh and has high actuality. One day of normal video production of a seminar may cost $25,000-$37,500. The production is typically accessible on the Internet from one week to fourteen days after the event. Experts are typically engaged that know about filming, digitization and encoding. An expert in creating Web pages is also usually needed.
A first problem in producing multimedia for the Internet is the large amount of tools a user has to manage. A second big issue is that it is time consuming. One hour of video takes about one hour to encode. A third problem is that if the user wants to have synchronized flipping images (from e.g., an overhead-projector etc.) there is a lot of work finding the synchronization points and creating the control files. A fourth problem is that the use of several cameras requires several camera operators.
Around the presentation or seminar there has to be at least one camera operator and often one person responsible for the sound and taking still pictures, with a digital still picture camera, of drawings at, for example, a whiteboard, notepad or overhead. A stopwatch is used to keep records of all still pictures when they are presented, because it is not always possible to figure out, from after-the-fact viewing of the movie of the speaker, what pictures to show as JPEG. Powerpoint slideshows etc., and other computer-based presentations are often sent as e-mail the day after the presentation, for conversion to JPEG or other suitable format by the production staff. It is, of course, possible to take stills at the same time as the pictures are presented, which is done when external presenters hold presentations.
The Powerpoint slides, when they arrive by e-mail, are (as mentioned above) converted to JPEG by the streaming production staff. The slides are also resized to fit in an HTML page together with the video window.
The production of streaming videos for 28.8K, 56K and 100K bit rates needs an extra window for the real information shown on slides, etc., because the video window is very small and the information in it is unreadable.
The video film is often manually edited with software like Adobe Premier. After editing, if any, the encoder is used to compress the video and audio to the correct baud-rate, and encode them to a streaming format like ASF (Active Streaming Format) or RMFF (Real Media File Format). The encoding takes the same amount of time as it takes to run through the movie. This is time consuming.
To be able to show the JPEG images (e.g. slide show) at the right time (compared to the movie events), synchronization points (time stamps) must be inserted in the stream file. In both Real Networks products and in Microsoft Netshow there are utilities available to do this. This typically requires an expert, even though the aforementioned tools have good user interfaces.
After all this has been accomplished, it is time to create HTML pages and frames. There has to be an HTML page for each picture.
It is therefore desirable in view of the foregoing to provide for distributing a visual presentation using Internet or another data network, without the aforementioned disadvantages of the prior art.
Embodiments of the present invention offer the ability to capture a full multimedia production such as a seminar, conference, lecture, etc. in real time using multiple cameras. A live movie of the speaker together with the speaker""s flipping still images or slide show can be viewed interactively within the same video display screen. The complete production can be stored on a hard drive or sent live to a host server. The information can be retrieved on demand or distributed live throughout a data network such as the Internet or corporate Intranet. It is also possible to store the complete presentation on CD or other portable storage media, and/or to send it as an e-mail to a PC.
According to the principles of the invention, the tools are handled automatically in the background, shielded from the user, and the encoding is done in real-time. The synchronization points are set when the event is really happening. In one example, overhead-projector plastic slides, computer VGA-graphics, whiteboard drawings, etc. are captured and converted to JPEG, and the video encoding is done in MPEG and stored together with the sound and synchronization points in an ASF file for RTSP (Real Time Streaming Protocol; see RFC 2326 published by IETF (www.IETF.org)) streaming.